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Author SHA1 Message Date
Yosry Ahmed
d2fbeb61e1 KVM: SVM: Move RAX legality check to SVM insn interception handlers
When #GP is intercepted by KVM, the #GP interception handler checks
whether the GPA in RAX is legal and reinjects the #GP accordingly.
Otherwise, it calls into the appropriate interception handler for
VMRUN/VMLOAD/VMSAVE. The intercept handlers do not check RAX.

However, the intercept handlers need to do the RAX check, because if the
guest has a smaller MAXPHYADDR, RAX could be legal from the hardware
perspective (i.e. CPU does not inject #GP), but not from the vCPU's
perspective. Note that with allow_smaller_maxphyaddr, both NPT and VLS
cannot be used, so VMLOAD/VMSAVE have to be intercepted, and RAX can
always be checked against the vCPU's MAXPHYADDR.

Move the check into the interception handlers for VMRUN/VMLOAD/VMSAVE as
the CPU does not check RAX before the interception. Read RAX using
kvm_register_read() to avoid a false negative on page_address_valid() on
32-bit due to garbage in the higher bits.

Keep the check in the #GP intercept handler in the nested case where
a #VMEXIT is synthesized into L1, as the RAX check is still needed there
and takes precedence over the intercept.

Opportunistically add a FIXME about the #VMEXIT being synthesized into
L1, as it needs to be conditional.

Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260316202732.3164936-5-yosry@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-04-03 16:08:02 -07:00
Yosry Ahmed
435741a4e7 KVM: SVM: Properly check RAX on #GP intercept of SVM instructions
When KVM intercepts #GP on an SVM instruction, it re-injects the #GP if
the instruction was executed with a mis-algined RAX. However, a #GP
should also be reinjected if RAX contains an illegal GPA, according to
the APM, one of #GP conditions is:

  rAX referenced a physical address above the maximum
  supported physical address.

Replace the PAGE_MASK check with page_address_valid(), which checks both
page-alignment as well as the legality of the GPA based on the vCPU's
MAXPHYADDR. Use kvm_register_read() to read RAX to so that bits 63:32 are
dropped when the vCPU is in 32-bit mode, i.e. to avoid a false positive
when checking the validity of the address.

Note that this is currently only a problem if KVM is running an L2 guest
and ends up synthesizing a #VMEXIT to L1, as the RAX check takes
precedence over the intercept. Otherwise, if KVM emulates the
instruction, kvm_vcpu_map() should fail on illegal GPAs and inject a #GP
anyway. However, following patches will change the failure behavior of
kvm_vcpu_map(), so make sure the #GP interception handler does this
appropriately.

Opportunistically drop a teaser FIXME about the SVM instructions
handling on #GP belonging in the emulator.

Fixes: 82a11e9c6f ("KVM: SVM: Add emulation support for #GP triggered by SVM instructions")
Fixes: d1cba6c922 ("KVM: x86: nSVM: test eax for 4K alignment for GP errata workaround")
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260316202732.3164936-4-yosry@kernel.org
[sean: massage wording with respect to kvm_register_read()]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-04-03 16:08:01 -07:00
Yosry Ahmed
27f70eaa86 KVM: SVM: Refactor SVM instruction handling on #GP intercept
Instead of returning an opcode from svm_instr_opcode() and then passing
it to emulate_svm_instr(), which uses it to find the corresponding exit
code and intercept handler, return the exit code directly from
svm_instr_opcode(), and rename it to svm_get_decoded_instr_exit_code().

emulate_svm_instr() boils down to synthesizing a #VMEXIT or calling the
intercept handler, so open-code it in gp_interception(), and use
svm_invoke_exit_handler() to call the intercept handler based on
the exit code. This allows for dropping the SVM_INSTR_* enum, and the
const array mapping its values to exit codes and intercept handlers.

In gp_intercept(), handle SVM instructions and first with an early return,
and invert is_guest_mode() checks, un-indenting the rest of the code.

No functional change intended.

Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260316202732.3164936-3-yosry@kernel.org
[sean: add BUILD_BUG_ON(), tweak formatting/naming]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-04-03 16:08:01 -07:00
Yosry Ahmed
c85aaff26d KVM: SVM: Properly check RAX in the emulator for SVM instructions
Architecturally, VMRUN/VMLOAD/VMSAVE should generate a #GP if the
physical address in RAX is not supported. check_svme_pa() hardcodes this
to checking that bits 63-48 are not set. This is incorrect on HW
supporting 52 bits of physical address space. Additionally, the emulator
does not check if the address is not aligned, which should also result
in #GP.

Use page_address_valid() which properly checks alignment and the address
legality based on the guest's MAXPHYADDR. Plumb it through
x86_emulate_ops, similar to is_canonical_addr(), to avoid directly
accessing the vCPU object in emulator code.

Fixes: 01de8b09e6 ("KVM: SVM: Add intercept checks for SVM instructions")
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260316202732.3164936-2-yosry@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-04-03 16:08:00 -07:00
Yoshihiro Shimoda
353d8e7989 net: ethernet: ravb: Suspend and resume the transmission flow
The current driver does not follow the latest datasheet and does not
suspend the flow when stopping DMA and resume it when starting. Update
the driver to do so.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[Niklas: Rebase from BSP and reword commit message]
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://patch.msgid.link/20260401183608.1852225-1-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 16:04:28 -07:00
Jakub Kicinski
1caa871bb0 Merge branch 'net-stmmac-fix-tegra234-mgbe-clock'
Jon Hunter says:

====================
net: stmmac: Fix Tegra234 MGBE clock

The name of the PTP ref clock for the Tegra234 MGBE ethernet controller
does not match the generic name in the stmmac platform driver. Despite
this basic ethernet is functional on the Tegra234 platforms that use
this driver and as far as I know, we have not tested PTP support with
this driver. Hence, the risk of breaking any functionality is low.

The previous attempt to fix this in the stmmac platform driver, by
supporting the Tegra234 PTP clock name, was rejected [0]. The preference
from the netdev maintainers is to fix this in the DT binding for
Tegra234.

This series fixes this by correcting the device-tree binding to align
with the generic name for the PTP clock. I understand that this is
breaking the ABI for this device, which we should never do, but this
is a last resort for getting this fixed. I am open to any better ideas
to fix this. Please note that we still maintain backward compatibility
in the driver to allow older device-trees to work, but we don't
advertise this via the binding, because I did not see any value in doing
so.
====================

Link: https://patch.msgid.link/20260401102941.17466-1-jonathanh@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 16:02:31 -07:00
Jon Hunter
fb22b1fc5b dt-bindings: net: Fix Tegra234 MGBE PTP clock
The PTP clock for the Tegra234 MGBE device is incorrectly named
'ptp-ref' and should be 'ptp_ref'. This is causing the following
warning to be observed on Tegra234 platforms that use this device:

 ERR KERN tegra-mgbe 6800000.ethernet eth0: Invalid PTP clock rate
 WARNING KERN tegra-mgbe 6800000.ethernet eth0: PTP init failed

Although this constitutes an ABI breakage in the binding for this
device, PTP support has clearly never worked and so fix this now
so we can correct the device-tree for this device. Note that the
MGBE driver still supports the legacy 'ptp-ref' clock name and so
older/existing device-trees will still work, but given that this
is not the correct name, there is no point to advertise this in the
binding.

Fixes: 189c2e5c76 ("dt-bindings: net: Add Tegra234 MGBE")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260401102941.17466-3-jonathanh@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 16:02:30 -07:00
Jon Hunter
1345e9f4e3 net: stmmac: Fix PTP ref clock for Tegra234
Since commit 030ce919e1 ("net: stmmac: make sure that ptp_rate is not
0 before configuring timestamping") was added the following error is
observed on Tegra234:

 ERR KERN tegra-mgbe 6800000.ethernet eth0: Invalid PTP clock rate
 WARNING KERN tegra-mgbe 6800000.ethernet eth0: PTP init failed

It turns out that the Tegra234 device-tree binding defines the PTP ref
clock name as 'ptp-ref' and not 'ptp_ref' and the above commit now
exposes this and that the PTP clock is not configured correctly.

In order to update device-tree to use the correct 'ptp_ref' name, update
the Tegra MGBE driver to use 'ptp_ref' by default and fallback to using
'ptp-ref' if this clock name is present.

Fixes: d8ca113724 ("net: stmmac: tegra: Add MGBE support")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260401102941.17466-2-jonathanh@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 16:02:21 -07:00
Pengpeng Hou
5c14a19d5b nfc: s3fwrn5: allocate rx skb before consuming bytes
s3fwrn82_uart_read() reports the number of accepted bytes to the serdev
core. The current code consumes bytes into recv_skb and may already
deliver a complete frame before allocating a fresh receive buffer.

If that alloc_skb() fails, the callback returns 0 even though it has
already consumed bytes, and it leaves recv_skb as NULL for the next
receive callback. That breaks the receive_buf() accounting contract and
can also lead to a NULL dereference on the next skb_put_u8().

Allocate the receive skb lazily before consuming the next byte instead.
If allocation fails, return the number of bytes already accepted.

Fixes: 3f52c2cb7e ("nfc: s3fwrn5: Support a UART interface")
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://patch.msgid.link/20260402042148.65236-1-pengpeng@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:57:46 -07:00
Naveen N Rao (AMD)
5635c8bfd3 x86/apic: Drop AMD Extended Interrupt LVT macros
AMD defines Extended Interrupt Local Vector Table (EILVT) registers to allow
for additional interrupt sources. While the APIC registers for those are
unique to AMD, the format of those registers follows the standard LVT
registers. Drop EILVT-specific macros in favor of the standard APIC
LVT macros.

Drop unused APIC_EILVT_NR_AMD_K8 and APIC_EILVT_LVTOFF while at it.

No functional change.

  [ bp: Merge the two cleanup patches into one. ]

Signed-off-by: Naveen N Rao (AMD) <naveen@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Manali Shukla <manali.shukla@amd.com>
Link: https://patch.msgid.link/b98d69037c0102d2ccd082a941888a689cd214c9.1775019269.git.naveen@kernel.org
2026-04-04 00:56:40 +02:00
Dave Jiang
bfbb6cb1b6 Merge branch 'for-7.1/cxl-misc' into cxl-for-next
MAINTAINERS: Update address for Dan Williams
2026-04-03 15:55:34 -07:00
Dan Williams
9b6e1ed28a MAINTAINERS: Update address for Dan Williams
Update MAINTAINERS and .mailmap to point to my kernel.org address:
djbw@kernel.org.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20260403214846.1062341-1-dan.j.williams@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-04-03 15:54:29 -07:00
Chris J Arges
77facb3522 net: increase IP_TUNNEL_RECURSION_LIMIT to 5
In configurations with multiple tunnel layers and MPLS lwtunnel routing, a
single tunnel hop can increment the counter beyond this limit. This causes
packets to be dropped with the "Dead loop on virtual device" message even
when a routing loop doesn't exist.

Increase IP_TUNNEL_RECURSION_LIMIT from 4 to 5 to handle this use-case.

Fixes: 6f1a9140ec ("net: add xmit recursion limit to tunnel xmit functions")
Link: https://lore.kernel.org/netdev/88deb91b-ef1b-403c-8eeb-0f971f27e34f@redhat.com/
Signed-off-by: Chris J Arges <carges@cloudflare.com>
Link: https://patch.msgid.link/20260402222401.3408368-1-carges@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:52:10 -07:00
Jakub Kicinski
48a5e77b49 Merge branch 'net-macb-remove-dedicated-irq-handler-for-wol'
Kevin Hao says:

====================
net: macb: Remove dedicated IRQ handler for WoL

During debugging of a suspend/resume issue, I observed that the macb driver
employs a dedicated IRQ handler for Wake-on-LAN (WoL) support. To my knowledge,
no other Ethernet driver adopts this approach. This implementation unnecessarily
complicates the suspend/resume process without providing any clear benefit.
Instead, we can easily modify the existing IRQ handler to manage WoL events,
avoiding any overhead in the TX/RX hot path.

The net throughput shows no significant difference following these changes.
The following data(net throughput and execution time of macb_interrupt) were
collected from my AMD Zynqmp board using the commands:
  taskset -c 1,2,3 iperf3 -c 192.168.3.4 -t 60 -Z -P 3 -R
  cat /sys/kernel/debug/tracing/trace_stat/function0

Before:
-------
  [SUM]   0.00-60.00  sec  5.99 GBytes   858 Mbits/sec    0             sender
  [SUM]   0.00-60.00  sec  5.99 GBytes   857 Mbits/sec                  receiver

  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  macb_interrupt                      217996    678425.2 us     3.112 us        1.446 us

After:
------
  [SUM]   0.00-60.00  sec  6.00 GBytes   858 Mbits/sec    0             sender
  [SUM]   0.00-60.00  sec  5.99 GBytes   857 Mbits/sec                  receiver

  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  macb_interrupt                      218212    668107.3 us     3.061 us        1.413 us
====================

Link: https://patch.msgid.link/20260402-macb-irq-v2-0-942d98ab1154@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:51:07 -07:00
Kevin Hao
6637c03f35 net: macb: Remove dedicated IRQ handler for WoL
In the current implementation, the suspend/resume path frees the
existing IRQ handler and sets up a dedicated WoL IRQ handler, then
restores the original handler upon resume. This approach is not used
by any other Ethernet driver and unnecessarily complicates the
suspend/resume process. After adjusting the IRQ handler in the previous
patches, we can now handle WoL interrupts without introducing any
overhead in the TX/RX hot path. Therefore, the dedicated WoL IRQ
handler is removed.

I have verified WoL functionality on my AMD ZynqMP board using the
following steps:
  root@amd-zynqmp:~# ifconfig end0 192.168.3.3
  root@amd-zynqmp:~# ethtool -s end0 wol a
  root@amd-zynqmp:~# echo mem >/sys/power/state

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://patch.msgid.link/20260402-macb-irq-v2-4-942d98ab1154@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:51:05 -07:00
Kevin Hao
6d55ce805b net: macb: Factor out the handling of non-hot IRQ events into a separate function
In the current code, the IRQ handler checks each IRQ event sequentially.
Since most IRQ events are related to TX/RX operations, while other
events occur infrequently, this approach introduces unnecessary overhead
in the hot path for TX/RX processing. This patch reduces such overhead
by extracting the handling of all non-TX/RX events into a new function
and consolidating these events under a new flag. As a result, only a
single check is required to determine whether any non-TX/RX events have
occurred. If such events exist, the handler jumps to the new function.
This optimization reduces four conditional checks to one and prevents
the instruction cache from being polluted with rarely used code in the
hot path.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://patch.msgid.link/20260402-macb-irq-v2-3-942d98ab1154@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:51:04 -07:00
Kevin Hao
5986ff6e41 net: macb: Introduce macb_queue_isr_clear() helper function
The current implementation includes several occurrences of the
following pattern:
	if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
		queue_writel(queue, ISR, value);

Introduces a helper function to consolidate these repeated code
segments. No functional changes are made.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://patch.msgid.link/20260402-macb-irq-v2-2-942d98ab1154@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:51:04 -07:00
Kevin Hao
dc3bd465ea net: macb: Replace open-coded implementation with napi_schedule()
The driver currently duplicates the logic of napi_schedule() primarily
to include additional debug information. However, these debug details
are not essential for a specific driver and can be effectively obtained
through existing tracepoints in the networking core, such as
/sys/kernel/tracing/events/napi/napi_poll. Therefore, this patch
replaces the open-coded implementation with napi_schedule() to
simplify the driver's code.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://patch.msgid.link/20260402-macb-irq-v2-1-942d98ab1154@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:51:04 -07:00
Danilo Krummrich
81d6f7c3a7 s390/ap: use generic driver_override infrastructure
When the AP masks are updated via apmask_store() or aqmask_store(),
ap_bus_revise_bindings() is called after ap_attr_mutex has been
released.

This calls __ap_revise_reserved(), which accesses the driver_override
field without holding any lock, racing against a concurrent
driver_override_store() that may free the old string, resulting in a
potential UAF.

Fix this by using the driver-core driver_override infrastructure, which
protects all accesses with an internal spinlock.

Note that unlike most other buses, the AP bus does not check
driver_override in its match() callback; the override is checked in
ap_device_probe() and __ap_revise_reserved() instead.

Also note that we do not enable the driver_override feature of struct
bus_type, as AP - in contrast to most other buses - passes "" to
sysfs_emit() when the driver_override pointer is NULL. Thus, printing
"\n" instead of "(null)\n".

Additionally, AP has a custom counter that is modified in the
corresponding custom driver_override_store().

Fixes: d38a87d7c0 ("s390/ap: Support driver_override for AP queue devices")
Tested-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Link: https://patch.msgid.link/20260324005919.2408620-11-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-04-04 00:49:22 +02:00
Danilo Krummrich
ac4d8bb6e2 s390/cio: use generic driver_override infrastructure
When a driver is probed through __driver_attach(), the bus' match()
callback is called without the device lock held, thus accessing the
driver_override field without a lock, which can cause a UAF.

Fix this by using the driver-core driver_override infrastructure taking
care of proper locking internally.

Note that calling match() from __driver_attach() without the device lock
held is intentional. [1]

Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1]
Reported-by: Gui-Dong Han <hanguidong02@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789
Fixes: ebc3d17915 ("s390/cio: introduce driver_override on the css bus")
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Link: https://patch.msgid.link/20260324005919.2408620-10-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-04-04 00:48:40 +02:00
Danilo Krummrich
85bb534ff1 vdpa: use generic driver_override infrastructure
When a driver is probed through __driver_attach(), the bus' match()
callback is called without the device lock held, thus accessing the
driver_override field without a lock, which can cause a UAF.

Fix this by using the driver-core driver_override infrastructure taking
care of proper locking internally.

Note that calling match() from __driver_attach() without the device lock
held is intentional. [1]

Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1]
Reported-by: Gui-Dong Han <hanguidong02@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789
Fixes: 539fec78ed ("vdpa: add driver_override support")
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://patch.msgid.link/20260324005919.2408620-9-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-04-04 00:47:50 +02:00
Yiqi Sun
fde29fd934 ipv4: icmp: fix null-ptr-deref in icmp_build_probe()
ipv6_stub->ipv6_dev_find() may return ERR_PTR(-EAFNOSUPPORT) when the
IPv6 stack is not active (CONFIG_IPV6=m and not loaded), and passing
this error pointer to dev_hold() will cause a kernel crash with
null-ptr-deref.

Instead, silently discard the request. RFC 8335 does not appear to
define a specific response for the case where an IPv6 interface
identifier is syntactically valid but the implementation cannot perform
the lookup at runtime, and silently dropping the request may safer than
misreporting "No Such Interface".

Fixes: d329ea5bd8 ("icmp: add response to RFC 8335 PROBE messages")
Signed-off-by: Yiqi Sun <sunyiqixm@gmail.com>
Link: https://patch.msgid.link/20260402070419.2291578-1-sunyiqixm@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:46:17 -07:00
Danilo Krummrich
8a700b1fc9 platform/wmi: use generic driver_override infrastructure
When a driver is probed through __driver_attach(), the bus' match()
callback is called without the device lock held, thus accessing the
driver_override field without a lock, which can cause a UAF.

Fix this by using the driver-core driver_override infrastructure taking
care of proper locking internally.

Note that calling match() from __driver_attach() without the device lock
held is intentional. [1]

Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1]
Reported-by: Gui-Dong Han <hanguidong02@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789
Fixes: 12046f8c77 ("platform/x86: wmi: Add driver_override support")
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260324005919.2408620-7-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-04-04 00:45:14 +02:00
Danilo Krummrich
10a4206a24 PCI: use generic driver_override infrastructure
When a driver is probed through __driver_attach(), the bus' match()
callback is called without the device lock held, thus accessing the
driver_override field without a lock, which can cause a UAF.

Fix this by using the driver-core driver_override infrastructure taking
care of proper locking internally.

Note that calling match() from __driver_attach() without the device lock
held is intentional. [1]

Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1]
Reported-by: Gui-Dong Han <hanguidong02@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789
Fixes: 782a985d7a ("PCI: Introduce new device binding path using pci_dev.driver_override")
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Williamson <alex@shazbot.org>
Tested-by: Gui-Dong Han <hanguidong02@gmail.com>
Reviewed-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://patch.msgid.link/20260324005919.2408620-6-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-04-04 00:44:30 +02:00
Qingfang Deng
779fae61a3 ppp: update Kconfig help message
Both links of the PPPoE section are no longer valid, and the CVS version
is no longer relevant.

- Replace the TLDP URL with the pppd project homepage.
- Update pppd version requirement for PPPoE.
- Update RP-PPPoE project homepage, and clarify that it's only needed
  for server mode.

Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev>
Reviewed-by: Julian Braha <julianbraha@gmail.com>
Link: https://patch.msgid.link/20260402050053.144250-1-qingfang.deng@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:35:13 -07:00
Fernando Fernandez Mancera
14cf0cd353 ipv4: nexthop: allocate skb dynamically in rtm_get_nexthop()
When querying a nexthop object via RTM_GETNEXTHOP, the kernel currently
allocates a fixed-size skb using NLMSG_GOODSIZE. While sufficient for
single nexthops and small Equal-Cost Multi-Path groups, this fixed
allocation fails for large nexthop groups like 512 nexthops.

This results in the following warning splat:

 WARNING: net/ipv4/nexthop.c:3395 at rtm_get_nexthop+0x176/0x1c0, CPU#20: rep/4608
 [...]
 RIP: 0010:rtm_get_nexthop (net/ipv4/nexthop.c:3395)
 [...]
 Call Trace:
  <TASK>
  rtnetlink_rcv_msg (net/core/rtnetlink.c:6989)
  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
  netlink_sendmsg (net/netlink/af_netlink.c:1894)
  ____sys_sendmsg (net/socket.c:721 net/socket.c:736 net/socket.c:2585)
  ___sys_sendmsg (net/socket.c:2641)
  __sys_sendmsg (net/socket.c:2671)
  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
  </TASK>

Fix this by allocating the size dynamically using nh_nlmsg_size() and
using nlmsg_new(), this is consistent with nexthop_notify() behavior. In
addition, adjust nh_nlmsg_size_grp() so it calculates the size needed
based on flags passed. While at it, also add the size of NHA_FDB for
nexthop group size calculation as it was missing too.

This cannot be reproduced via iproute2 as the group size is currently
limited and the command fails as follows:

addattr_l ERROR: message exceeded bound of 1048

Fixes: 430a049190 ("nexthop: Add support for nexthop groups")
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Closes: https://lore.kernel.org/netdev/CAL_bE8Li2h4KO+AQFXW4S6Yb_u5X4oSKnkywW+LPFjuErhqELA@mail.gmail.com/
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260402072613.25262-2-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:34:27 -07:00
Fernando Fernandez Mancera
06aaf04ca8 ipv4: nexthop: avoid duplicate NHA_HW_STATS_ENABLE on nexthop group dump
Currently NHA_HW_STATS_ENABLE is included twice everytime a dump of
nexthop group is performed with NHA_OP_FLAG_DUMP_STATS. As all the stats
querying were moved to nla_put_nh_group_stats(), leave only that
instance of the attribute querying.

Fixes: 5072ae00ae ("net: nexthop: Expose nexthop group HW stats to user space")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260402072613.25262-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:34:27 -07:00
Bartosz Golaszewski
1cf996ac30 driver core: make software nodes available earlier
Software nodes are currently initialized in a function registered as
a postcore_initcall(). However, some devices may want to register
software nodes earlier than that (or also in a postcore_initcall() where
they're at the mercy of the link order). Move the initialization to
driver_init() making swnode available much earlier as well as making
their initialization time deterministic.

Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260402-nokia770-gpio-swnodes-v5-3-d730db3dd299@oss.qualcomm.com
[ Fix typo in the commit message: "s/merci/mercy/". - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-04-04 00:33:49 +02:00
Pengpeng Hou
b76254c55d net: qualcomm: qca_uart: report the consumed byte on RX skb allocation failure
qca_tty_receive() consumes each input byte before checking whether a
completed frame needs a fresh receive skb. When the current byte completes
a frame, the driver delivers that frame and then allocates a new skb for
the next one.

If that allocation fails, the current code returns i even though data[i]
has already been consumed and may already have completed the delivered
frame. Since serdev interprets the return value as the number of accepted
bytes, this under-reports progress by one byte and can replay the final
byte of the completed frame into a fresh parser state on the next call.

Return i + 1 in that failure path so the accepted-byte count matches the
actual receive-state progress.

Fixes: dfc768fbe6 ("net: qualcomm: add QCA7000 UART driver")
Cc: stable@vger.kernel.org
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Reviewed-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260402071207.4036-1-pengpeng@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:32:56 -07:00
Oleh Konko
48a5fe3877 tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG
The GRP_ACK_MSG handler in tipc_group_proto_rcv() currently decrements
bc_ackers on every inbound group ACK, even when the same member has
already acknowledged the current broadcast round.

Because bc_ackers is a u16, a duplicate ACK received after the last
legitimate ACK wraps the counter to 65535. Once wrapped,
tipc_group_bc_cong() keeps reporting congestion and later group
broadcasts on the affected socket stay blocked until the group is
recreated.

Fix this by ignoring duplicate or stale ACKs before touching bc_acked or
bc_ackers. This makes repeated GRP_ACK_MSG handling idempotent and
prevents the underflow path.

Fixes: 2f487712b8 ("tipc: guarantee that group broadcast doesn't bypass group unicast")
Cc: stable@vger.kernel.org
Signed-off-by: Oleh Konko <security@1seal.org>
Reviewed-by: Tung Nguyen <tung.quang.nguyen@est.tech>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/41a4833f368641218e444fdcff822039.security@1seal.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:31:17 -07:00
Eric Dumazet
1666d945b5 inet: remove leftover EXPORT_SYMBOL()
IPv6 is no longer a module, we no longer need to export these symbols.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260402174430.2462800-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:07:46 -07:00
Nikolaos Gkarlis
7b735ef812 rtnetlink: add missing netlink_ns_capable() check for peer netns
rtnl_newlink() lacks a CAP_NET_ADMIN capability check on the peer
network namespace when creating paired devices (veth, vxcan,
netkit). This allows an unprivileged user with a user namespace
to create interfaces in arbitrary network namespaces, including
init_net.

Add a netlink_ns_capable() check for CAP_NET_ADMIN in the peer
namespace before allowing device creation to proceed.

Fixes: 81adee47df ("net: Support specifying the network namespace upon device creation.")
Signed-off-by: Nikolaos Gkarlis <nickgarlis@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260402181432.4126920-1-nickgarlis@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:07:18 -07:00
Jakub Kicinski
071fe8b5d5 Merge branch 'selftests-drv-net-gro-more-test-cases'
Jakub Kicinski says:

====================
selftests: drv-net: gro: more test cases

Add a few more test cases for GRO.

First 4 patches are unchanged from v1.

Patches 5 and 6 are new. Willem pointed out that the defines are
duplicated and all these imprecise defines have been annoying me
for a while so I decided to clean them up.

With the defines cleaned up and now more precise patch 7 (was 5)
no longer has to play any games with the MTU for ip6ip6.

The last patch now sends 3 segments as requested.
====================

Link: https://patch.msgid.link/20260402210000.1512696-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:48 -07:00
Jakub Kicinski
764d0833e7 selftests: drv-net: gro: add a test for bad IPv4 csum
We have a test for coalescing with bad TCP checksum, let's also
test bad IPv4 header checksum.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260402210000.1512696-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:45 -07:00
Jakub Kicinski
9a84a4047d selftests: drv-net: gro: test ip6ip6
We explicitly test ipip encap. Let's add ip6ip6, too. Having
just ipip seems like favoring IPv4 which we should not do :)
Testing all combinations is left for future work, not sure
it's actually worth it.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260402210000.1512696-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:44 -07:00
Jakub Kicinski
024597cc20 selftests: drv-net: gro: make large packet math more precise
When constructing the packets for large_* test cases we use
a static value for packet count and MSS. It works okay for
ipv4 vs ipv6 but the gap between ipv4 and ip6ip6 is going to
be quite significant.

Make the defines calculate the worst case values, those
are only used for sizing stack arrays. Create helpers for
calculating precise values based on the exact test case.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260402210000.1512696-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:44 -07:00
Jakub Kicinski
166b0cc6df selftests: drv-net: gro: remove TOTAL_HDR_LEN
Willem points out TOTAL_HDR_LEN is identical to MAX_HDR_LEN.
This seems to have been the case ever since the test was added.
Replace the uses of TOTAL_HDR_LEN with MAX_HDR_LEN, MAX seems
more common for what this value is.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260402210000.1512696-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:44 -07:00
Jakub Kicinski
5469b695f2 selftests: drv-net: gro: prepare for ip6ip6 support
Try to use already calculated offsets and not depend on the ipip
flag as much. This patch should not change any functionality,
it's just a cleanup to make ip6ip6 support easier.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260402210000.1512696-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:43 -07:00
Jakub Kicinski
d973484747 selftests: drv-net: gro: always wait for FIN in the capacity test
The new capacity/order test exits as soon as it sees the expected
packet sequence. This may allow the "flushing" FIN packet to spill
over to the next test. Let's always wait for the FIN before exiting.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260402210000.1512696-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:43 -07:00
Jakub Kicinski
436ea8a1b7 selftests: drv-net: gro: add 1 byte payload test
Small IPv4 packets get padded to 60B, this may break / confuse
some buggy implementations. Add a test to coalesce a 1B payload.
Keep this separate from the lrg_sml test because I suspect some
implementations may not handle this case (treat padded frames
as ineligible for coalescing).

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260402210000.1512696-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:43 -07:00
Jakub Kicinski
30f831b44a selftests: drv-net: gro: add data burst test case
Add a test trying to induce a GRO context timeout followed
by another sequence of packets for the same flow. The second
burst arrives 100ms after the first one so any implementation
(SW or HW) must time out waiting at that point. We expect both
bursts to be aggregated successfully but separately.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260402210000.1512696-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 15:05:42 -07:00
Richard Zhu
3a4e8302e7 PCI: imx6: Keep Root Port MSI capability with iMSI-RX to work around hardware bug
On NXP i.MX7D, i.MX8MM, and i.MX8MQ chipsets, MSIs from the endpoints won't
be received by the iMSI-RX MSI controller if the Root Port MSI capability
is disabled.

Even though the Root Port MSIs won't be received by the iMSI-RX controller
due to design, these chipsets have some weird hardware bug that prevents
the endpoint MSIs from reaching when the Root Port MSI capability is
disabled.

Hence, introduce a new flag, 'dw_pcie_rp::keep_rp_msi_en', set it for the
above mentioned SoCs, and always keep the Root Port MSI capability when
this flag is set.

Note that by keeping Root Port MSI capability, Root Port MSIs such as AER,
PME and others won't be received by default. So users need to use
workarounds such as passing 'pcie_pme=nomsi' cmdline param.

Fixes: f5cd8a929c ("PCI: dwc: Remove MSI/MSIX capability for Root Port if iMSI-RX is used as MSI controller")
Suggested-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
[mani: commit log]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
[bhelgaas: fix typos]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260331085252.1243108-1-hongxing.zhu@nxp.com
2026-04-03 16:51:27 -05:00
Zijing Yin
1979645e18 bridge: guard local VLAN-0 FDB helpers against NULL vlan group
When CONFIG_BRIDGE_VLAN_FILTERING is not set, br_vlan_group() and
nbp_vlan_group() return NULL (br_private.h stub definitions). The
BR_BOOLOPT_FDB_LOCAL_VLAN_0 toggle code is compiled unconditionally and
reaches br_fdb_delete_locals_per_vlan_port() and
br_fdb_insert_locals_per_vlan_port(), where the NULL vlan group pointer
is dereferenced via list_for_each_entry(v, &vg->vlan_list, vlist).

The observed crash is in the delete path, triggered when creating a
bridge with IFLA_BR_MULTI_BOOLOPT containing BR_BOOLOPT_FDB_LOCAL_VLAN_0
via RTM_NEWLINK. The insert helper has the same bug pattern.

  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000056: 0000 [#1] KASAN NOPTI
  KASAN: null-ptr-deref in range [0x00000000000002b0-0x00000000000002b7]
  RIP: 0010:br_fdb_delete_locals_per_vlan+0x2b9/0x310
  Call Trace:
   br_fdb_toggle_local_vlan_0+0x452/0x4c0
   br_toggle_fdb_local_vlan_0+0x31/0x80 net/bridge/br.c:276
   br_boolopt_toggle net/bridge/br.c:313
   br_boolopt_multi_toggle net/bridge/br.c:364
   br_changelink net/bridge/br_netlink.c:1542
   br_dev_newlink net/bridge/br_netlink.c:1575

Add NULL checks for the vlan group pointer in both helpers, returning
early when there are no VLANs to iterate. This matches the existing
pattern used by other bridge FDB functions such as br_fdb_add() and
br_fdb_delete().

Fixes: 21446c06b4 ("net: bridge: Introduce UAPI for BR_BOOLOPT_FDB_LOCAL_VLAN_0")
Signed-off-by: Zijing Yin <yzjaurora@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402140153.3925663-1-yzjaurora@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 14:45:51 -07:00
Eric Dumazet
4e65a8b8da ipv6: ioam: fix potential NULL dereferences in __ioam6_fill_trace_data()
We need to check __in6_dev_get() for possible NULL value, as
suggested by Yiming Qian.

Also add skb_dst_dev_rcu() instead of skb_dst_dev(),
and two missing READ_ONCE().

Note that @dev can't be NULL.

Fixes: 9ee11f0fff ("ipv6: ioam: Data plane support for Pre-allocated Trace")
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Justin Iurman <justin.iurman@gmail.com>
Link: https://patch.msgid.link/20260402101732.1188059-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 14:44:43 -07:00
Lorenzo Bianconi
285fa6b1e0 net: airoha: Fix memory leak in airoha_qdma_rx_process()
If an error occurs on the subsequents buffers belonging to the
non-linear part of the skb (e.g. due to an error in the payload length
reported by the NIC or if we consumed all the available fragments for
the skb), the page_pool fragment will not be linked to the skb so it will
not return to the pool in the airoha_qdma_rx_process() error path. Fix the
memory leak partially reverting commit 'd6d2b0e153 ("net: airoha: Fix
page recycling in airoha_qdma_rx_process()")' and always running
page_pool_put_full_page routine in the airoha_qdma_rx_process() error
path.

Fixes: d6d2b0e153 ("net: airoha: Fix page recycling in airoha_qdma_rx_process()")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260402-airoha_qdma_rx_process-mem-leak-fix-v1-1-b5706f402d3c@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 14:42:51 -07:00
Eric Dumazet
b120e4432f net: lapbether: handle NETDEV_PRE_TYPE_CHANGE
lapbeth_data_transmit() expects the underlying device type
to be ARPHRD_ETHER.

Returning NOTIFY_BAD from lapbeth_device_event() makes sure
bonding driver can not break this expectation.

Fixes: 872254dd6b ("net/bonding: Enable bonding to enslave non ARPHRD_ETHER")
Reported-by: syzbot+d8c285748fa7292580a9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/69cd22a1.050a0220.70c3a.0002.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin Schiller <ms@dev.tdt.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260402103519.1201565-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 14:40:36 -07:00
Arnd Bergmann
e16a0d3677 net: fec: make FIXED_PHY dependency unconditional
When CONFIG_FIXED_PHY is in a loadable module, the fec driver cannot be
built-in any more:

x86_64-linux-ld: vmlinux.o: in function `fec_enet_mii_probe':
fec_main.c:(.text+0xc4f367): undefined reference to `fixed_phy_unregister'
x86_64-linux-ld: vmlinux.o: in function `fec_enet_close':
fec_main.c:(.text+0xc59591): undefined reference to `fixed_phy_unregister'
x86_64-linux-ld: vmlinux.o: in function `fec_enet_mii_probe.cold':

Select the fixed phy support on all targets to make this build
correctly, not just on coldfire.

Notat that Essentially the stub helpers in include/linux/phy_fixed.h
cannot be used correctly because of this build time dependency,
and we could just remove them to hit the build failure more often
when a driver uses them without the 'select FIXED_PHY'.

Fixes: dc86b621e1 ("net: fec: register a fixed phy using fixed_phy_register_100fd if needed")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260402141048.2713445-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03 14:39:37 -07:00
Gerd Bayer
8e69214402 PCI: Update PCIe spec references for AtomicOps
Point to the relevant sections in the most recent release 7.0 of the PCIe
spec. Text has mostly just moved around without any semantic change.

Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260330-fix_pciatops-v7-3-f601818417e8@linux.ibm.com
2026-04-03 16:39:31 -05:00
Gerd Bayer
1ae8c4ce15 PCI: Enable AtomicOps only if Root Port supports them
When inspecting the config space of a Connect-X physical function in an
s390 system after it was initialized by the mlx5_core device driver, we
found the function to be enabled to request AtomicOps despite the Root Port
lacking support for completing them:

  00:00.1 Ethernet controller: Mellanox Technologies MT2894 Family [ConnectX-6 Lx]
          Subsystem: Mellanox Technologies Device 0002
          DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-
                   AtomicOpsCtl: ReqEn+

On s390 and many virtualized guests, the Endpoint is visible but the Root
Port is not.  In this case, pci_enable_atomic_ops_to_root() previously
enabled AtomicOps in the Endpoint even though it can't tell whether the
Root Port supports them as a completer.

Change pci_enable_atomic_ops_to_root() to fail if there's no Root Port or
the Root Port doesn't support AtomicOps.

Fixes: 430a23689d ("PCI: Add pci_enable_atomic_ops_to_root()")
Reported-by: Alexander Schmidt <alexs@linux.ibm.com>
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
[bhelgaas: commit log, check RP first to simplify flow]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260330-fix_pciatops-v7-2-f601818417e8@linux.ibm.com
2026-04-03 16:39:31 -05:00
Gerd Bayer
03ec922f00 PCI: Do not enable AtomicOps by RCiEPs
Since Root Complex Integrated Endpoints (RCiEPs) attach to a bus that has
no bridge device describing the Root Port, the capability to complete
AtomicOps requests cannot be determined with PCIe methods.

Change default of pci_enable_atomic_ops_to_root() to not enable AtomicOps
requests on RCiEPs.

As far as we know, there are no RCiEPs that need AtomicOps (see Link
below).

Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260330-fix_pciatops-v7-1-f601818417e8@linux.ibm.com
2026-04-03 16:39:21 -05:00